The Y86 version of the max(int numbers[], int len) function. Finds the greatest number in an array of ints. Comments are... non-standard.

max.y86.asm

.text
.globl max
max:
pushl %ebp
movl %esp, %ebp

mrmovl 8(%esp), %ecx
rrmovl %ecx, %eax      #; pointer to numbers[]
mrmovl (%ecx), %ecx    #; ecx holds greatest encountered
                       #; number
mrmovl 12(%ebp), %edx  #; len/counter
irmovl $1, %esi  #; incrimenter
irmovl $4, %edi  #; another incrimenter
jmp .compare

.new_greatest:
mrmovl (%eax), %ecx  #; change greatest to value (%eax)

.loop:
subl %esi, %edx  #; decrease counter
addl %edi, %eax  #; incriment %eax by 4 to get next num

mrmovl (%eax), %ebx #; ebx holds value (%eax)
subl %ecx, %ebx     #; greatest - ebx
jg .new_greatest    #; if greater, then %ebx > %ecx

.compare
subl %esi, %edx  #; subtract 1 from counter
jg .loop         #; if counter > 0, loop again

rrmovl %ecx, %eax #; move highest into return space
popl %ebp
ret